We were flying into Toronto Pearsons Int six days ago when the 744 ahead of us reported a near-miss with a small sized UFO (either a bird or a drone, suspected latter). They did sound a bit worried during transmission to ATC but as usual, ATC replied with, paraphrasing here, "nothing is on my radar so therefore it is not my problem".
Shame really. Looks like we are going to have to share the skies with birds AND drones now...